1. Field of the Invention
This invention concerns air bag safety devices for auto vehicles which have been devised to be deployed during a severe collision to cushion the driver and/or passengers to prevent or reduce the severity of injuries.
2. Description of the Prior Art
In air bag installations, an air bag "cannister", comprised of a receptacle holding a folded air bag and an inflation apparatus, is stored behind a section of an auto interior trim panel, such as the instrument panel (passenger side bag) or steering wheel cover (driver side bag). The air bag is inflated to be deployed within the passenger compartment as the collision occurs, and thus must enter the passenger compartment through an opening in the trim panel. Typically, a pair of doors are installed in a vertical rear facing surface of the instrument panel (mid mount) or steering wheel cover, or a single door is provided in an upper surface of the instrument panel (top mount). The doors are designed to be opened by the air bag as it inflates during deployment.
A drawback to the prior designs is that the doors are exteriorly visible, i.e., are apparent to the driver or passenger seated in the passenger compartment, which visibility creates a mild state of apprehension in some persons.
Also, the separate door construction adds to the cost of the interior trim, and may adversely affect the aesthetics of the interior finishing.
Examples of such deployment door designs are described in copending applications Ser. No. 241,893 filed on Sept. 8, 1988 now U.S. Pat. No. 4,893,833 and Ser. No. 258,890 filed on Oct. 17, 1988 now U.S. Pat. No. 4,989,896.
It is an object of the present invention to provide a method and apparatus for forming an air bag deployment opening in an interior trim panel in which there is no visible delineation of the opening prior to activation of the air bag.
It is a further object of the present invention to provide such method and apparatus which does not require a separate door closure assembly to be installed in the interior trim piece defining the opening, and which is simple and failsafe in operation.